Date to Unix Timestamp
Convert date to Unix timestamp online. Paste ISO 8601 strings or numeric timestamps; get Unix seconds and milliseconds instantly. Free, browser-local, no upload.
Runs locally in your browser. Your input is not uploaded to DevToolMate servers.
Developer Quick Tips
- Paste ISO 8601 strings like 2026-08-23T10:00:00Z or numeric timestamps; output shows both Unix seconds and milliseconds instantly.
- Values below 1e12 are seconds; larger values are milliseconds. Check the unit label to avoid off-by-1000 bugs in production code.
- ISO 8601 with Z or numeric offsets like +05:30 are supported; invalid input returns a clear error message.
- All processing runs in your browser. No upload, no account, no server calls. Press Ctrl or Cmd + Enter to convert.
- Use Unix Timestamp to Date for the reverse conversion and full calendar view with time zone options.
Frequently asked questions
How do I convert a date to Unix timestamp online?
Paste an ISO 8601 date string (e.g., 2026-08-23T10:00:00Z) or a numeric timestamp into the input field. The tool instantly outputs Unix seconds and milliseconds. No upload, no account required; all processing runs in your browser.
What formats does this date to Unix timestamp converter accept?
The tool accepts ISO 8601 strings with Z (UTC) or numeric offsets like +05:30. Examples: 2026-08-23T10:00:00Z or 2026-08-23T10:00:00+05:30. Numeric timestamps are also supported. Invalid dates return a friendly error.
What is the difference between Unix seconds and milliseconds?
Unix seconds count from January 1, 1970 UTC. Milliseconds are 1000x larger. This tool uses a heuristic: values below 1e12 are treated as seconds; larger values are milliseconds. Always check the unit label in the output.
Can I convert Unix timestamp to date with this tool?
No. This tool converts dates to Unix timestamps. For the reverse conversion (Unix timestamp to date), use the Unix Timestamp to Date tool on DevToolMate, which also provides full calendar output and time zone options.
Does this tool store my input after I close the tab?
No. Input stays in memory only while the page is open. Closing the tab clears it. Theme preference is stored locally in your browser but is not tool input data.
Does this tool validate timestamps against a network time source?
No. This tool parses dates using your browser's JavaScript Date implementation. It does not connect to a network time authority or validate against external sources. Use it for local conversion only.
Related tools
- Unix Timestamp to Date: Convert Unix timestamp to date online instantly. Auto-detects seconds vs milliseconds. Get ISO 8601, UTC, and local time. Browser-local, no upload.